"I'm not aware of anyone having died from chickenpox?": Acceptability of varicella vaccination in the UK, a mixed methods questionnaire and interview study.

Introduction: Chickenpox (varicella) contributes to a large number of hospitalisations in the United Kingdom (UK) where vaccination is not routine, and can result in serious complications. The varicella vaccine was recommended for inclusion in the UK routine immunisation schedule by the Joint Committee on Vaccination and Immunisation (JCVI) in November 2023. A systematic review identified no previous qualitative studies investigating UK parents' views regarding chickenpox and vaccination.

Objective: To explore parents' views of chickenpox and varicella vaccination, and identify barriers and facilitators to this and other childhood vaccinations.

Methods: Underpinned by sequential mixed-methodology a quantitative cross-sectional online survey (n = 609), distributed via nurseries and social media, and qualitative semi-structured interviews (n = 12) with a sub-sample of survey respondents. Descriptive statistical analysis was undertaken on quantitative data. Qualitative data were interpreted by reflexive thematic analysis, according to the EQUATOR network standards for reporting qualitative research. Findings were analysed separately, and integrated equally using a triangulation protocol for validation or repudiation.

Findings: Integration demonstrated parents perceived chickenpox as a common, typically mild, childhood illness. Parents held few concerns, with most worries focussing on severe infection risk, and impact on time off school or work. Most would accept routine varicella vaccination, though had concerns about duration of immunity. Many questioned necessity of vaccination, and whether natural immunity was superior. Non-vaccinating parents hold distinct concerns relating to safety, vaccine contents, and their synthetic nature.

Discussion And Conclusion: Whilst most parents are accepting of vaccination, they hold specific concerns related to varicella vaccination which may result in sub-optimal uptake for critical herd immunity. To achieve this it will be crucial to raise awareness of the potential risks of chickenpox, and address concerns identified. Many parents seek reliable vaccine information from healthcare professionals, and so appropriate education and training should be considered, including communicating risks and benefits of vaccination, which may be beneficial antenatally.